Optimization unit for real-time applications in unbalanced smart distribution networks.

This paper presents a new generic approach for developing a Jacobian matrix for use with the optimization unit in real-time energy management systems (EMS) for unbalanced smart distribution systems. The proposed formulation can replace approximated calculations for real-time optimal power flow in an optimization unit while providing greater accuracy and requiring less computational time, which is critical for real-time EMS. The effectiveness and robustness of the proposed approach have been tested through simulations with different distribution networks. The simulation results demonstrate a significant reduction in the computational time with the new proposed formulation. Moreover, the results demonstrate the scalability of the proposed approach as the reduction in the computational time is more significant for large practical systems. The proposed approach is characterized by evaluating the scalability and low computational time; thus, it can be used by grid operators in real-time energy management applications for large-scale practical distribution systems.

Anti-acetylcholinesterase potential and metabolome classification of 4 Ocimum species as determined via UPLC/qTOF/MS and chemometric tools.

Ocimum (sweet basil) is a plant of considerable commercial importance in traditional medicine worldwide as well as for the flavor and food industry. The goal of this study was to examine Ocimum extracts anti-acetylcholinesterase activity and to correlate the activity with their secondary metabolites profiles via a metabolome based ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) approach coupled to chemometrics. The metabolomic differences in phenolics from leaves derived from 4 Ocimum species: Ocimum basilicum, Ocimum africanum, Ocimum americanum and Ocimum minimum were assessed. Under optimized conditions, 81 metabolites were identified including 21 hydroxy cinnamic acids, 4 benzoic acid conjugates, 14C/O flavonoid conjugates, 2 alcohols, 5 acyl sugars, 4 triterpenes and 12 fatty acids. Several salviolanic acid derivatives including salviolanic acid A, B, C & I found in Salvia, were found in Ocimum herein for the first time. Unsupervised principal component analysis (PCA) and supervised orthogonal projection to latent structures-discriminant analysis (OPLS-DA) were further used for comparing and classification of samples. A clear separation among the four investigated Ocimum species was revealed, with O. africanum samples found most enriched in hydroxy cinnamates conjugates (HC) and flavonoids. To the best of our knowledge, this is the first report for compositional differences among Ocimum leaves via a metabolomic approach revealing that among examined species O. africanum leaves present a better source of Ocimum bioactive metabolites. The anticholinesrase activity of examined species was further assessed with a potent IC50 values for O. americanum, O. africanum, O. basilicum ranging from 2.5 to 6.6mg/ml, whereas O. minimum was least active with IC50 of 31.4mg/ml. Furthermore, major HC i.e., caftaric, chlorogenic and rosmarinic acids identified in extracts via UPLC-MS analysis exhibited IC50 values of 24, 0.5 and 7.9mg/ml respectively, suggesting that HCs are likely to mediate for the anticholinesterase effect in Ocimum extracts.

3-D flexible nano-textured high-density microelectrode arrays for high-performance neuro-monitoring and neuro-stimulation.

We introduce a new 3-D flexible microelectrode array for high performance electrographic neural signal recording and stimulation. The microelectrode architecture maximizes the number of channels on each shank and minimizes its footprint. The electrode was implemented on flexible polyimide substrate using microfabrication and thin-film processing. The electrode has a planar layout and comprises multiple shanks. Each shank is three mm in length and carries six gold pads representing the neuro-interfacing channels. The channels are used in recording important precursors with potential clinical relevance and consequent electrical stimulation to perturb the clinical condition. The polyimide structure satisfied the mechanical characteristics required for the proper electrode implantation and operation. Pad postprocessing technique was developed to improve the electrode electrical performance. The planar electrodes were used for creating 3-D "Waterloo Array" microelectrode with controlled gaps using custom designed stackers. Electrode characterization and benchmarking against commercial equivalents demonstrated the superiority of the Flex electrodes. The Flex and commercial electrodes were associated with low-power implantable responsive neuro-stimulation system. The electrodes performance in recording and stimulation application was quantified through in vitro and in vivo acute and chronic experiments on human brain slices and freely-moving rodents. The Flex electrodes exhibited remarkable drop in the electric impedance (100 times at 100 Hz), improved electrode-electrolyte interface noise (dropped by four times) and higher signal-to-noise ratio (3.3 times).

Blindness and Visual Impairment among Egyptian Glaucoma Patients.

Purpose. Glaucoma is the second commonest cause of blindness worldwide. Visual fields and intraocular pressures are optimum outcomes to be assessed in developed countries. Visual acuity as an outcome is the key player when assessing blindness in developing countries. The aim of this study is to assess visual impairment and blindness in glaucoma patients and to identify the bulk they represent in comparison to nonglaucoma patients in the same practice setting. Methods. Patients attending outpatient clinics of Cairo University Hospitals were enrolled in this cross-sectional study. Clinical data collected for these patients included their demographic data, best obtained visual acuity, and whether or not they have had an established diagnosis of glaucoma. Results were compared at 95% confidence intervals. Results. 988 eyes of 494 patients were included for this study. Their mean visual acuity was 6/24 (±3 Snellen lines). Legal blindness was found in 5% and 4% of glaucoma and nonglaucoma groups, respectively. There were high odds for finding eyes with total blindness due to glaucoma. That was statistically significant (P < 0.05). Conclusions. A large proportion of glaucoma patients suffered from blindness in at least one eye. Interventional strategies are recommended regarding visual disability among Egyptian glaucoma patients.

High-density intracortical microelectrode arrays with multiple metallization layers for fine-resolution neuromonitoring and neurostimulation.

Intracortical microelectrodes play a prominent role in the operation of neural interfacing systems. They provide an interface for recording neural activities and modulating their behavior through electric stimulation. The performance of such systems is thus directly meliorated by advances in electrode technology. We present a new architecture for intracortical electrodes designed to increase the number of recording/stimulation channels for a given set of shank dimensions. The architecture was implemented on silicon using microfabrication process and fabricated 3-mm-long electrode shanks with six relatively large (110 µm ×110 µm) pads in each shank for electrographic signal recording to detect important precursors with potential clinical relevance and electrical stimulation to correct neural behavior with low-power dissipation in an implantable device. Moreover, an electrode mechanical design was developed to increase its stiffness and reduce shank deflection to improve spatial accuracy during an electrode implantation. Furthermore, the pads were post-processed using pulsated low current electroplating and reduced their impedances by ≈ 30 times compared to the traditionally fabricated pads. The paper also presents microfabrication process, electrodes characterization, comparison to the commercial equivalents, and in vitro and in vivo validations.

Massively-parallel neuromonitoring and neurostimulation rodent headset with nanotextured flexible microelectrodes.

We present a compact wireless headset for simultaneous multi-site neuromonitoring and neurostimulation in the rodent brain. The system comprises flexible-shaft microelectrodes, neural amplifiers, neurostimulators, a digital time-division multiplexer (TDM), a micro-controller and a ZigBee wireless transceiver. The system is built by parallelizing up to four 0.35 µm CMOS integrated circuits (each having 256 neural amplifiers and 64 neurostimulators) to provide a total maximum of 1024 neural amplifiers and 256 neurostimulators. Each bipolar neural amplifier features 54 dB-72 dB adjustable gain, 1 Hz-5 kHz adjustable bandwidth with an input-referred noise of 7.99 µVrms and dissipates 12.9 µW. Each current-mode bipolar neurostimulator generates programmable arbitrary-waveform biphasic current in the range of 20-250 µA and dissipates 2.6 µW in the stand-by mode. Reconfigurability is provided by stacking a set of dedicated mini-PCBs that share a common signaling bus within as small as 22 × 30 × 15 mm³ volume. The system features flexible polyimide-based microelectrode array design that is not brittle and increases pad packing density. Pad nanotexturing by electrodeposition reduces the electrode-tissue interface impedance from an average of 2 MΩ to 30 kΩ at 100 Hz. The rodent headset and the microelectrode array have been experimentally validated in vivo in freely moving rats for two months. We demonstrate 92.8 percent seizure rate reduction by responsive neurostimulation in an acute epilepsy rat model.

Resistance to low-dose aspirin therapy among patients with acute coronary syndrome in relation to associated risk factors.

BACKGROUND: A substantial proportion of patients have recurrence of vascular events despite daily intake of low-dose aspirin therapy. Therefore, different patients may require different aspirin dosages to achieve complete inhibition of platelet function. OBJECTIVE: The aim of this work was to measure the response to low-dose aspirin therapy (150 mg/day) among patients with unstable angina or non-ST-segment elevation myocardial infarction and to find out whether titrating aspirin dosage to 300 mg/day, would provide a better therapeutic response in the resistant cases. Moreover, we also aimed to study any association between aspirin non-responsiveness and atherothrombotic risk factors. METHODS: The antiplatelet effect of 150 mg/day aspirin was studied prospectively in 50 consecutive patients with unstable angina or non-ST-segment elevation myocardial infarction. Platelet aggregation was measured using optical platelet aggregometry and serum thromboxane B(2) level. Aspirin resistance was defined as collagen (1 µg/mL) and adenosine diphosphate (ADP) (5 µmol/L)-induced platelet aggregation of ≥ 40% when compared with control values. Twenty healthy age- and sex-matched individuals were taken as a control group. All patients were subjected to complete medical history (risk factors, medications), thorough clinical examination, ECG, coronary angiography and laboratory investigations including: complete haemogram, coagulation, kidney, liver and lipid profiles, fasting blood glucose and glycated haemoglobin (HbA(1C) ). RESULTS: Eleven of 50 patients (22%) were found to be aspirin resistant. A highly significant difference was found between the mean values of ADP, collagen-induced platelet aggregation percentage and thromboxane B(2) level after aspirin 150 mg/day when compared with the corresponding mean values after aspirin 300 mg/day among the resistant patients (66 ± 7.01%, 62 ± 4.34% and 620 ± 64.58 pg/mL, respectively, vs. 26.87 ± 2.85%, 16.5 ± 3.8% and 77 ± 11.3 pg/mL) indicating enhanced response to aspirin after escalating the dose. The presence of atherothrombotic risk factors (hypertension, smoking, family history of ischaemic heart disease and previous MI) were not statistically different between aspirin-resistant and aspirin-sensitive patients. However, there was a highly significant difference between the aspirin sensitive and the resistant patients regarding the other risk factors (diabetes mellitus and dyslipidaemia) (P < 0.01). CONCLUSION: There is inter-individual variability in response to the antiplatelet effect of standard doses of aspirin (150, 300 mg/day). The response to aspirin 300 mg/day is enhanced in resistant patients when compared to 150 mg/day. There was a significant association between aspirin resistance and atherothrombotic risk factors (diabetes, hyperlipidaemia and obesity).

Validated spectrofluorimetric method for the determination of atorvastatin in pharmaceutical preparations / 药物分析学报

A rapid,sensitive and simple spectrofluorimetric method was developed for the estimation of atorvastatin.In this method,the native fluorescence characteristics of atorvastatin have been studied in both acidic and basic media.High sensitivity was obtained with 5％ acetic acid at 389 nm using 276 nm for excitation.Regression analysis showed a good correlation coefficient (r=0.9995) between fluorescence intensity and concentration over the range of 1.5-4 μg/mL with detection limit of 0.012 μg/mL.The proposed method was successfully applied to the analysis of atorvastatin in pure and pharmaceutical dosage forms with average recovery of 100.29±0.47％.The results were compared favorably with those of the reported method.

An automated neural-fuzzy approach to malignant tumor localization in 2D ultrasonic images of the prostate.

In this paper, a new neural-fuzzy approach is proposed for automated region segmentation in transrectal ultrasound images of the prostate. The goal of region segmentation is to identify suspicious regions in the prostate in order to provide decision support for the diagnosis of prostate cancer. The new automated region segmentation system uses expert knowledge as well as both textural and spatial features in the image to accomplish the segmentation. The textural information is extracted by two recurrent random pulsed neural networks trained by two sets of data (a suspicious tissues' data set and a normal tissues' data set). Spatial information is captured by the atlas-based reference approach and is represented as fuzzy membership functions. The textural and spatial features are synthesized by a fuzzy inference system, which provides a binary classification of the region to be evaluated.

Finite difference time domain (FDTD) modeling of implanted deep brain stimulation electrodes and brain tissue.

This paper demonstrates the electromagnetic modeling and simulation of an implanted Medtronic deep brain stimulation (DBS) electrode using finite difference time domain (FDTD). The model is developed using Empire XCcel and represents the electrode surrounded with brain tissue assuming homogenous and isotropic medium. The model is created to study the parameters influencing the electric field distribution within the tissue in order to provide reference and benchmarking data for DBS and intra-cortical electrode development.

Prostate tissue texture feature extraction for suspicious regions identification on TRUS images.

In this work, two different approaches are proposed for region of interest (ROI) segmentation using transrectal ultrasound (TRUS) images. The two methods aim to extract informative features that are able to characterize suspicious regions in the TRUS images. Both proposed methods are based on multi-resolution analysis that is characterized by its high localization in both the frequency and the spatial domains. Being highly localized in both domains, the proposed methods are expected to accurately identify the suspicious ROIs. On one hand, the first method depends on a Gabor filter that captures the high frequency changes in the image regions. On the other hand, the second method depends on classifying the wavelet coefficients of the image. It is shown in this paper that both methods reveal details in the ROIs which correlate with their pathological representations. It was found that there is a good match between the regions identified using the two methods, a result that supports the ability of each of the proposed methods to mimic the radiologist's decision in identifying suspicious regions. Studying two ROI segmentation methods is important since the only available dataset is the radiologist's suspicious regions, and there is a need to support the results obtained by either one of the proposed methods. This work is mainly a preliminary proof of concept study that will ultimately be expanded to a larger scale study whose aim will be introducing an assisting tool to help the radiologist identify the suspicious regions.

Real-time automated neural-network sleep classifier using single channel EEG recording for detection of narcolepsy episodes.

Conventional sleep staging and classification methods involve complicated settings to acquire multiple electrophysiological signals for extended recording durations, followed by specialists' analysis which is a time consuming exercise. These procedures need to be carried out in sleep clinics and are not suitable for applications based on real-time sleep monitoring and analysis. In this paper, a real-time sleep staging and classification technique is proposed using single EEG channel based on an artificial neural network classifier. This method is optimized to run on portable processing platforms with limited processing capabilities.

Design optimization methodology for dry EEG spikes array electrode.

Monitoring bio-electric events is a vital practice which provides medical data required in many clinical and research applications. Improving the performance of portable and ambulatory recording devices requires developing stable biomedical electrodes suitable for long term recording. This paper introduces an optimization design methodology to improve the electrical performance of dry electrodes used in electroencephalography through optimizing the geometrical design while abiding by design constraints which guarantee biocompatibility and mechanical stability.

Prostate cancer multi-feature analysis using trans-rectal ultrasound images.

This note focuses on extracting and analysing prostate texture features from trans-rectal ultrasound (TRUS) images for tissue characterization. One of the principal contributions of this investigation is the use of the information of the images' frequency domain features and spatial domain features to attain a more accurate diagnosis. Each image is divided into regions of interest (ROIs) by the Gabor multi-resolution analysis, a crucial stage, in which segmentation is achieved according to the frequency response of the image pixels. The pixels with a similar response to the same filter are grouped to form one ROI. Next, from each ROI two different statistical feature sets are constructed; the first set includes four grey level dependence matrix (GLDM) features and the second set consists of five grey level difference vector (GLDV) features. These constructed feature sets are then ranked by the mutual information feature selection (MIFS) algorithm. Here, the features that provide the maximum mutual information of each feature and class (cancerous and non-cancerous) and the minimum mutual information of the selected features are chosen, yielding a reduced feature subset. The two constructed feature sets, GLDM and GLDV, as well as the reduced feature subset, are examined in terms of three different classifiers: the condensed k-nearest neighbour (CNN), the decision tree (DT) and the support vector machine (SVM). The accuracy classification results range from 87.5% to 93.75%, where the performance of the SVM and that of the DT are significantly better than the performance of the CNN.

Prostate segmentation algorithm using dyadic wavelet transform and discrete dynamic contour.

Knowing the location and the volume of the prostate is important for ultrasound-guided prostate brachytherapy, a commonly used prostate cancer treatment method. The prostate boundary must be segmented before a dose plan can be obtained. However, manual segmentation is arduous and time consuming. This paper introduces a semi-automatic segmentation algorithm based on the dyadic wavelet transform (DWT) and the discrete dynamic contour (DDC). A spline interpolation method is used to determine the initial contour based on four user-defined initial points. The DDC model then refines the initial contour based on the approximate coefficients and the wavelet coefficients generated using the DWT. The DDC model is executed under two settings. The coefficients used in these two settings are derived using smoothing functions with different sizes. A selection rule is used to choose the best contour based on the contours produced in these two settings. The accuracy of the final contour produced by the proposed algorithm is evaluated by comparing it with the manual contour outlined by an expert observer. A total of 114 2D TRUS images taken for six different patients scheduled for brachytherapy were segmented using the proposed algorithm. The average difference between the contour segmented using the proposed algorithm and the manually outlined contour is less than 3 pixels.

Prevalence and intensity of schistosomiasis haematobium among school children in respect of family social conditions in a village in Dakahlia Governorate, Egypt.

A probability sample (n = 2000) of primary and preparatory school children (6-15 years old) in a rural area, in the eastern part of Nile Delta, Egypt, were examined for S. haematobium eggs using the sedimentation technique. A sub-sample, consisting of all children whose urine samples were positive, was subjected to short interview and urine examination for egg counting using the modern monofilament polyamide (Nytrel) filters. The overall prevalence of S. haematobium was 5.5% with significant (P < 0.05) difference between males (7.9%) and females (3.1%). The sample mean egg count was 163 eggs/10 ml urine, while those of males and females were 625 and 52, respectively (P < 0.001). The age category 9-12 years old had the highest prevalence rate and mean egg count. Also, these patients had highest frequency distributions in the severe grade of infection intensity. Significant relationships were detected between fathers' occupation and mothers' education on one hand and mean egg counts and intensity grade of infection on the other hand.

Serological and histopathological studies on toxoplasma Gondii among the workers and the slaughtered animals in Tanta Abattoir, Gharbia Governorate.

Toxoplasma gondii is one of the important zoonotic parasite of worldwide zoological and geographical distribution. In this paper, Toxoplasma antibodies were investigated among workers (21) and slaughtered animals (258) in Tanta abattoir. The indirect haemagglutination test (IHAT) was positive among workers (52.4%) at titers 1/64, 1/256, 1/512 and slaughtered animals (44.1%), at titers > 1:64. The indirect fluorescent antibody test (IFAT done for animals only) was positive (48.8%) at titers 1/40. Histopathological study on infected prescapular lymph nodes of the examined animals showed different clinical pictures, which coincided with the serological results. It was concluded that meat should not be consumed uncooked or undercooked.

Serum levels of tumour necrosis factor alpha (TNF-alpha) versus immunoglobulins (IgG., IgM., and IgE.) in Egyptian scabietic children.

The tumour necrosis factor-alpha (TNF-alpha or Cachectin) is a protein produced mainly by macrophages, with a wide range of biological activities and in inflammatory process. On the other hand, scabies is a skin disease caused by Sarcoptes scabiei which is typified by severe itching (particularly at night), red papules and often secondary infection. The female mite tunnels in the skin to lay her eggs and the newly hatched mites pass easily from person to person by contact. Commonly the infested areas are the groin, penis, nipples and the skin between the fingers. In this paper, the serum levels of TNF-alpha versus IgG., IgM., and IgE. were estimated in parasitologically proven scabietic male children (8-13 years) with no secondary infection or other parasitic infection. The results showed high significant elevation of serum TNF-alpha in 94.1% (P = 7.763E-04) and IgE in 100% (P = 1.530E-07) in the scabietic patients than in the control group, and non significant increase in IgG in 47% (P = 0.0605) and in IgM in 5.9% (P = 0.9404). It was concluded that TNF-alpha plays a role in the pathogenesis of human scabies. Extensive study is ongoing to clarify the outcome of TNF-alpha in human scabies.

Studies on anopheline larvae in El Faiyum Governorate, Egypt.

In Egypt, malaria is still reported as sporadic cases or small outbreaks particularly in El Faiyum Governorate. This paper aimed to identify and to study the breeding and seasonal activities of anopheline larvae. Spot light surveys were carried out in five different ecological areas (Karoun Lake, El Fedemean, El Siliyien, Kom-Osheim and Sinouris) from September 1991 to August 1992. Three species of Anopheles larvae were encountered: A. (Cellia) pharoensis (43%), A. (Cellia) sergenti (29.8%) and A. (Cellia) multicolor (27.2%). Several type of breeding places were encountered for the three species. A. pharoensis preferred clear, shallow, stagnant water with thick growth of vegetations an shae especially in rice fields. A. sergenti preferred clean, shallow to deep stagnant or slow-moving water with vegetations especially in small water collections in grassy areas and under palm trees. A. multicolor preferred shallow, stagnant water, sometimes partially exposed to sunlight especially in seepage water. The breeding waters for the three species were alkaline. Seasonal study of the anopheline larvae were conducted in three villages: Abheit El Hagar, El Zawia El Khadra and Tersa, in Sinouris Center during the year 1993. A. pharoensis larvae were abundant in the three villages in June, July, August and September with a peak in June. No breeding was noticed in January and February. A. sergenti larvae were abundant from September to November in the three villages, the lowest density was recorded in January and July in Abheit, in April in El Zawia and in June in Tersa. No breeding in February in the three villages was noticed and also in March in Abheit and Tersa. A multicolor larvae were recorded in Abheit and Tersa. In Abheit, the highest density was recorded in November with no breeding in January, February, March and June while in Tersa, the highest density was recorded in October and November with no breeding in January, February, March, April, July and December. The whole results were discussed.

Four species of house dust mites recovered from houses of patients with allergic respiratory diseases.

Arthropods and their products are wide spread and considered one of the common allergens affecting man. Allergy to arthropod antigens is the major cause of respiratory allergy as rhinitis and bronchial asthma. The range of reaction depends on several factors which include the type and source of the material, the rate of intensity, the duration of exposure, the human immune response and history of prior exposure. Successful management of allergic disease depends on proper identification of the causative allergen and reduce exposure to this allergen. Generally speaking, the house dust is not a simple substance but an accumulation of living and non living parts as mites, pollens, molds, dander and decaying insects. In the present study, four species of mites were isolated from the dust collected from the houses of patients with allergic respiratory diseases. The species were Dermatophagoides pteronyssinus, D. farinae, Ornithonyssus bacoti and Haemogamassus pontiger. The two species of Dermatophagoides. were the predominant mites which are known to produce the most potent allergies. Studying the serum immunoglobulins level showed that the IgE had a highly significant concentration among respiratory allergic patients (28) with (5) or without (23) atopic dermatitis. It was concluded that house dust mites, that cause inhalant allergens, are one of the main aetiological factors of allergic respiratory diseases, with or without atopic dermatitis.